Several drug interaction checkers are available online that can help you determine if your prescription drugs may interact with each other, as well as over-the-counter drugs, vitamins, dietary supplements, food, and alcoholic beverages. See below for a few which don't require you to sign up or divulge any personal details.

A year after receiving approval by the Food and Drug Administration, the new weight-loss drug Belviq is finally available by prescription. But you may not want to rush out and get it. It's only approved for people who are obese, with a body-mass index of 30 or more, or who are overweight, with a BMI between 27 and 30, and also have diabetes, high blood pressure, or high cholesterol. But our medical advisers say skip the drug, and lose weight other ways. Here's why:

You have a few choices: Ask your doctor to prescribe a different drug from your insurance company's formulary. If that's not possible or your doctor says it's not a good idea, have your doctor petition your insurance company to cover the drug. If your health plan denies your request, you can file an appeal.

Perhaps prompted by all the ads for drugs such as AndroGel 1.62% and Axiron, many men attribute their lagging libido to reduced testosterone levels. But stress, depression, lack of sleep or exercise, work load, or changed feelings about your partner can all have the same negative effect on your sex drive without affecting your testosterone level.

Yes. Acetaminophen (Tylenol and generic) is actually a better choice than Advil, Motrin, or related drugs for people who take a daily aspirin but need relief for minor aches and pains.

Yes. Not all pharmacies offer the full array of vaccines recommended for overseas travel. But if one in your area provides that service, it's certainly a safe, convenient way to get the immunizations you need to help you stay healthy on your trip.

Testosterone drugs such as Androgel 1.62% and Axiron increase the risk of heart attacks, strokes, and other cardiovascular events in men who take the drugs. Children accidentally exposed to testosterone can experience early puberty, and women who touch the stuff can experience acne and the growth of body hair. Need another reason to steer clear of the drugs? Consider this: The gels are flammable.

Not from your vet. They sharply mark up their drug prices, and tack on a $5 to $15 dispensing fee, according to the American Animal Hospital Association. For many pet meds, a better bet is your local pharmacy.

Not if the screening device scans your heel to capture your bone density measurement, instead of the lower spine or hip. Bone density measurements help determine if you have osteoporosis. But heel scans can be inaccurate, say our medical consultants. The problem is that "normal" results could provide a false sense of security. For a better assessment, and to help determine whether you even need the test at all, discuss with your doctor.

Think a pill that packs two cholesterol-lowering drugs in one potent package is a good idea? The Food and Drug Administration thinks so. It recently approved the combination of the popular statin drug Lipitor (atorvastatin) with another medication called Zetia (ezetimbe). But our medical advisers say the new product, Liptruzet, is too risky and too expensive.

Emergency-room visits stemming from Ambien, Edluar, Zolpimist, and other insomnia drugs containing zolpidem have more than tripled in recent years, according to a new report.

Superstorm Sandy devastated not just homes and property, but people's ability to get needed health care, too. A quarter of the people in our survey of online subscribers in Connecticut, New Jersey, and New York said Sandy caused medical hardships, especially with getting prescription drugs by mail and closed pharmacies.

If you've ever had trouble affording your medications and wanted to call your doctor on it, here's some encouraging news: Doctors aren't pleased about the prices either. Denouncing "profiteering" by pharmaceutical companies, more than 100 cancer doctors and researchers specializing in treating the blood cancer chronic myeloid leukemia (CML) argued the pressing need to lower cancer drug prices in a paper published last week in the journal Blood. And the doctors noted that the costs of prescription drugs, combined with medical illnesses, are the "the single most frequent cause of personal bankruptcies."

About a year after they expire. In most cases, prescription-drug expiration dates are one year to five years from the date they were made. But some pills can actually keep for a decade or even longer, research suggests. "Except for tetracycline, which can become toxic and cause kidney problems, expired drugs generally don't appear to cause harm," says Consumer Reports' chief medical advisor, Marvin M. Lipman, M.D. "But they do become less potent over time."

Walmart and Target win out over drugstore chains like Rite-Aid, CVS, and Walgreens, as well as supermarkets, on prices for dozens of common, brand-name and generic over-the-counter drugs, according to our team of Secret Shoppers.